Organització nuclear dels gens que codifiquen per a les proteïnes làcties en cèlules epitelials mamàries en diferents estadis de desenvolupament

Estudi realitzat a partir d’una estada al Institut National de la Recherche Agronomique (INRA), a França, entre 2006 i 2008. En el ultims anys, estudis realitzats en diferents tipus cel•lulars han pogut determinar l’importància de l’organització nuclear en el control i regulació gènica. S’han realizat diferents experiments per tal de determinar si la posició dels gens de les proteïnes làcties en el nucli interfàsic de cel•lules epitelials mamaries és important per regular la seva expressió. Els gens de les proteïnes de la llet s’expressen a la glàndula mamaria durant la lactació en resposta a les hormones lactogèniques (majoritàriament prolactina i glucocorticoids). Mitjançant la tècnica de FISH (fluorescent in situ hibridization) en 3D s’ha caracteritzat la localització nuclear del gens WAP (whey acidic protein) i les caseïnes en cèl•lules epitelials mamaries de ratolí (HC11) cultivades en l’absència i presencia d’hormones lactogèniques. En absència d’hormones, els dos gens estan distribuïts dins del nucli de forma no aleatòria, el gen WAP es troba localitzat en l’interior del nucli, mentre que les caseïnes es troben localitzades prop de la perifèria nuclear. L’estimulació hormonal indueix un canvi significatiu en la distància dels dos gens a la perifèria nuclear. Així mateix, la posició del locus de la caseïna en relació al seu territori cromosòmic (CT) 5 està correlacionada amb la inducció hormonal i per tant amb la seva activació transcripcional, mentre que la posició del gen WAP amb relació al seu CT11 sembla més determinada pel context cromosòmic del gen. Per últim, no s’han trobat diferencies en la localització dels gens en relació a l'heterocromatina del centròmer, descrit com a compartiment repressiu, entre les cèl•lules estimulades amb hormones i les que no. En els dos casos s’ha trobat un gran percentatge de gens que no estan associats als centròmers.

Acceso a la Biblioteca de la UOC por medio de la telefonía móvil

La Universitat Oberta de Catalunya, va començar al febrer del 2000, a oferir part dels continguts del Campus Virtual per mitjà del WAP de primera generació.

M-Library in an m-University : changing Models in the Open University of Catalonia

The general perspective of M-technologies and M-Services at the Spanish universities is not still in a very high level when we are ending the first decade of the 21st century. Some Universities and some of their libraries are starting to try out with M-technologies, but are still far from a model of massive exploitation, less than in some other countries. A deep study is needed to know the main reasons, study that we will not do in this paper. This general perspective does not mean that there are no significant initiatives which start to trust in M-technologies from Universities and their libraries. Models based in M-technologies make more sense than ever in open universities and in open libraries. That's the reason why the UOC's Library began in late 90s its first experiences in the M-Technologies and M-Libraries developments. In 1999 the appropriate technology offered the opportunity to carry out the first pilot test with SMS, and then applying the WAP technology. At those moments we managed to link-up mobile phones to the OPAC through a WAP system that allowed searching the catalogue by categories and finding the final location of a document, offering also the address of the library in which the user could loan it. Since then, UOC (and its library) directs its efforts towards adapting the offer of services to all sorts of M-devices used by end users. Left the WAP technology, nowadays the library is experimenting with some new devices like e-books, and some new services to get more feedback through the OPAC and metalibrary search products. We propose the case of Open University of Catalonia, in two levels: M-services applied in the library and M-technologies applied in some other university services and resources.

Evaluating the probability and the impact of a failure in GMPLS based networks

In this paper, we define a new scheme to develop and evaluate protection strategies for building reliable GMPLS networks. This is based on what we have called the network protection degree (NPD). The NPD consists of an a priori evaluation, the failure sensibility degree (FSD), which provides the failure probability, and an a posteriori evaluation, the failure impact degree (FID), which determines the impact on the network in case of failure, in terms of packet loss and recovery time. Having mathematical formulated these components, experimental results demonstrate the benefits of the utilization of the NPD, when used to enhance some current QoS routing algorithms in order to offer a certain degree of protection

Minimum interference routing with fast protection

One of the most effective techniques offering QoS routing is minimum interference routing. However, it is complex in terms of computation time and is not oriented toward improving the network protection level. In order to include better levels of protection, new minimum interference routing algorithms are necessary. Minimizing the failure recovery time is also a complex process involving different failure recovery phases. Some of these phases depend completely on correct routing selection, such as minimizing the failure notification time. The level of protection also involves other aspects, such as the amount of resources used. In this case shared backup techniques should be considered. Therefore, minimum interference techniques should also be modified in order to include sharing resources for protection in their objectives. These aspects are reviewed and analyzed in this article, and a new proposal combining minimum interference with fast protection using shared segment backups is introduced. Results show that our proposed method improves both minimization of the request rejection ratio and the percentage of bandwidth allocated to backup paths in networks with low and medium protection requirements

Resource dimensioning aspect of heterogeneous traffic with different service requirements: Integration versus segregation

In this paper, we consider the ATM networks in which the virtual path concept is implemented. The question of how to multiplex two or more diverse traffic classes while providing different quality of service requirements is a very complicated open problem. Two distinct options are available: integration and segregation. In an integration approach all the traffic from different connections are multiplexed onto one VP. This implies that the most restrictive QOS requirements must be applied to all services. Therefore, link utilization will be decreased because unnecessarily stringent QOS is provided to all connections. With the segregation approach the problem can be much simplified if different types of traffic are separated by assigning a VP with dedicated resources (buffers and links). Therefore, resources may not be efficiently utilized because no sharing of bandwidth can take place across the VP. The probability that the bandwidth required by the accepted connections exceeds the capacity of the link is evaluated with the probability of congestion (PC). Since the PC can be expressed as the CLP, we shall simply carry out bandwidth allocation using the PC. We first focus on the influence of some parameters (CLP, bit rate and burstiness) on the capacity required by a VP supporting a single traffic class using the new convolution approach. Numerical results are presented both to compare the required capacity and to observe which conditions under each approach are preferred

Enhanced multi-layer protection in multi-service GMPLS networks

This paper focuses on QoS routing with protection in an MPLS network over an optical layer. In this multi-layer scenario each layer deploys its own fault management methods. A partially protected optical layer is proposed and the rest of the network is protected at the MPLS layer. New protection schemes that avoid protection duplications are proposed. Moreover, this paper also introduces a new traffic classification based on the level of reliability. The failure impact is evaluated in terms of recovery time depending on the traffic class. The proposed schemes also include a novel variation of minimum interference routing and shared segment backup computation. A complete set of experiments proves that the proposed schemes are more efficient as compared to the previous ones, in terms of resources used to protect the network, failure impact and the request rejection ratio

Lightweight monitoring of label switched paths for bandwidth management

The purpose of resource management is the efficient and effective use of network resources, for instance bandwidth. In this article, a connection oriented network scenario is considered, where a certain amount of bandwidth is reserved for each label switch path (LSP), which is a logical path, in a MPLS or GMPLS environment. Assuming there is also some kind of admission control (explicit or implicit), these environments typically provide quality of service (QoS) guarantees. It could happen that some LSPs become busy, thus rejecting connections, while other LSPs may be under-utilised. We propose a distributed lightweight monitoring technique, based on threshold values, the objective of which is to detect congestion when it occurs in an LSP and activate the corresponding alarm which will trigger a dynamic bandwidth reallocation mechanism

Entorn de simulació per a xarxes òptiques de transport

Aquest projecte final de carrera pretén investigar i experimentar una nova línia de desenvolupament d’algorismes dinàmics. A partir de l’algorisme AntNet-QoS [2] s’ incorporen noves mesures a l’algorisme (mesura de l’amplada de banda disponible i jitter), les quals combinant amb la mesura de retard ja feta servir, permet adaptar-se millor a les condicions actuals del trànsit en la xarxa i als requeriments específics de qualitat (QoS) per part del trànsit

CAC controlled services sharing a link with connectionless data services in an ATM network: a performance evaluation study

In the B-ISDN there is a provision for four classes of services, all of them supported by a single transport network (the ATM network). Three of these services, the connected oriented (CO) ones, permit connection access control (CAC) but the fourth, the connectionless oriented (CLO) one, does not. Therefore, when CLO service and CO services have to share the same ATM link, a conflict may arise. This is because a bandwidth allocation to obtain maximum statistical gain can damage the contracted ATM quality of service (QOS); and vice versa, in order to guarantee the contracted QOS, the statistical gain have to be sacrificed. The paper presents a performance evaluation study of the influence of the CLO service on a CO service (a circuit emulation service or a variable bit-rate service) when sharing the same link

Resource management research in Passive Optical Networks (PON)

Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. It is plausible to assume that, from a technological standpoint, the Future Internet will be composed of long-range high-speed optical networks; a number of wireless networks at the edge; and, in between, several access technologies, among which, the Passive Optical Networks (xPON) are very likely to succeed, due to their simplicity, low-cost, and increased bandwidth. Among the different PON technologies, the Ethernet-PON (EPON) is the most promising alternative to satisfy operator and user needs, due to its cost, flexibility and interoperability with other technologies. One of the most interesting challenges in such technologies relates to the scheduling and allocation of resources in the upstream (shared) channel. The aim of this research project is to study and evaluate current contributions and propose new efficient solutions to address the resource allocation issues in Next Generation EPON (NG-EPON). Key issues in this context are future end-user needs, integrated quality of service (QoS) support and optimized service provisioning for real time and elastic flows. This project will unveil research opportunities, issue recommendations and propose novel mechanisms associated with the convergence within heterogeneous access networks and will thus serve as a basis for long-term research projects in this direction. The project has served as a platform for the generation of new concepts and solutions that were published in national and international conferences, scientific journals and also in book chapter. We expect some more research publications in addition to the ones mentioned to be generated in a few months.

A simulation-based algorithm for solving the resource-assignment problem in satellite telecommunication networks

This paper proposes an heuristic for the scheduling of capacity requests and the periodic assignment of radio resources in geostationary (GEO) satellite networks with star topology, using the Demand Assigned Multiple Access (DAMA) protocol in the link layer, and Multi-Frequency Time Division Multiple Access (MF-TDMA) and Adaptive Coding and Modulation (ACM) in the physical layer.

Estudi / implementació de la Qualitat de Servei en els entorns de xarxa i CPU

En aquest treball final de carrera es realitza estudi, així com la implementació, de la QoS (Quality of Service) en els entorns de xarxa i CPU sota el sistema operatiu Linux. L'objectiu és garantir uns determinats amples de banda, així com reservar porcions de CPU a través del nucli del S.O., per determinades aplicacions. D'aquesta manera es podrà obtenir una execució més eficient d'aquestes aplicacions.

Metro Ethernet -tekniikka: verkko, palvelut ja suunnittelu

Työ aloitettiin perehtymällä Metro Ethernet verkon eriosiin kuten Ethernet-verkkoon, MultiProtocol Label Switching verkkoon ja näiden verkkojen eriosiin. Työssä siis tarkasteltiin lähemmin Ethernet verkon toimintaa sekä sen tarjoamia standardeja kaistannopeuteen, kaapeli materiaaleihin ja kehysrakenteeseen. Tarkasteltiin myös MultiProtocol Label Swit-ching verkon rakennetta, pakettien reititys perusteita pohjautuen Ethernet verkon kehysrakenteeseen, Internet Protocol over MultiProtocol Label Switching tekniikkaa sekä näihin liittyviä alakäsitteitä kuten palvelunlaatu, virtuaaliyhteys, MAC-osoite jne. Kun työssä oli selvitetty Metro Ethernet verkon taustat ja perusteet voitiin siirtyä tutkimaan Metro Area Network ja Metro Ethernet Networks verkkojen tarkempaa rakennetta ja niiden mahdollisuuksia. Koska työn aiheena on Metro Ethernet-verkko, tulee myös tutkia Metro Ethernet Forum järjestöä jossa päätetään kaikki Metro Ethernet-verkkoon liittyvät asiat ja mm. MEF standardit. MEF standardeja on 16 kappaletta ja ne määrittelevät mm. Metro Ethernet verkon palvelut ja verkon arkkitehtuurin. Viimeisenä tutkimusalueena oli kolmen eri verkkolaitteen tutkiminen ja jo valmiina olevien verkkolaitteiden mahdollisuuksien kartoitus. Laitteiden tutkinnassa perehdyttiin Metro Et-hernet-verkko mahdollisuuksiin jokaisen laitevalmistajan tarjoamalla Internet Protocol over MultiProtocol Label Switching tekniikalla. Lopuksi tutkittiin vielä verkkosuunnitelman poh-jan luomista sekä itse suunnitelmaa, aikaisempien tutkimus tulosten pohjalle. Tutkimuksen tuloksena saatiin Metro Ethernet verkon ja käyttökelpoisten verkkolaitteiden tutkimusraportti ja käyttökelpoinen Metro Ethernet-verkkosuunnitelma jota voi käyttää mahdollisesti suoraan pohjana tai ainakin vertailu pohjana käytännön toteutuksessa.

Avaliação dos Serviços VoIP em Links de Baixa Capacidade com Tráfego Compartilhado de Dados

Esta dissertação descreve os resultados das medições observadas em um dos Laboratórios de uma Operadora de Telecomunicações (LOP), onde foram avaliados e analisados alguns requisitos de QoS em redes de pacotes IP (Internet Protocol). Essas medições foram feitas no âmbito do objetivo desta dissertação que é avaliar formas de prover serviços VoIP (Voice over Internet Protocol) em redes de pacotes conforme a recomendação do padrão FRF.12. Essa rede é assim, uma rede de link de 512kbps que também provê serviços VoIP compartilhados, concorrentemente com dados e serviços multimídia. Dos ítens analisados destacam-se: Análise de Codecs; QoS (Quality Of Service) Diffserv; Compressão de cabeçalho RTP (Real Time Protocol) - cRTP; Fragmentação com intercalação - LFI; Comportamento da Rede em situações diversas; a adequação do software free Multi Generator (MGEN) de geração - medição - coleta de dados, em redes. A análise foi, essencialmente, em enlace Frame Relay nos CPE (Customer Premise Equipment), passando pelo Backbone IP VPN / MPLS Multicast, pois o Frame Relay Fórum v12 (FRF.12) dá suporte à intercalação de voz entre os pacotes de dados. O FRF.12 é indispensável, pois este esta dissertação tem como objetivo realizar um conjuntos de testes e medidas que avaliam a aplicação dos serviços VoIP em links de baixa capacidades com trafego de dados compartilhados. Para oferecer esse serviço e de qualidade é necessário fragmentar e intercalar frames de voz entre os pacotes de dados usando o FRF.12. Depois do estudo teórico das recomendações, normas de padronização internacional e dos fabricantes, foram realizados testes que resultam na validação prática de toda a teoria outrora analisada através de testes específicos que comprovam em definitivo a viabilidade das aplicações VoIP em uma rede de enlace de baixa velocidade. Feitos esses testes chegou-se a conclusão de que em determinados casos não se revela necessário nem preocupante o aumento da banda para se puder prover determinados serviços. Na sequência dos testes foram também avaliados o desempenho, a ocupação da banda e a eficácia dos equipamentos - softwares. Da bancada dos testes e medições, provou-se o seguinte: que de fato consegue-se melhor otimização da banda ao realizar compressão do cabeçalho cRTP; que de fato a fragmentação de pacote FTP (File Transfer Protocol) com intercalação de pacotes VoIP faz reduzir o delay e jitter1 para as aplicações de tempo real; que de fato a habilitação de QoS Intserv provê classificação e faz diferenciação dos tráfegos, e que o CODEC G729 apresenta melhor adequação em lidar com aplicações VoIP em routers2 CISCO, disponível em CRT (Centro de referência Tecnológica) de uma LOP.